WO2006063503A1

WO2006063503A1 - Varistor with an alloy-type temperature fuse

Info

Publication number: WO2006063503A1
Application number: PCT/CN2005/001810
Authority: WO
Inventors: Zhonghou Xu
Original assignee: Zhonghou Xu
Priority date: 2004-12-13
Filing date: 2005-11-01
Publication date: 2006-06-22
Also published as: EP1826780B1; EP1826780A4; CA2588819C; CA2588819A1; US20080088405A1; EP1826780A1; US8780521B2

Abstract

A varistor with an alloy-type temperature fuse is disclosed, comprising a varistor, an alloy-type temperature fuse, a closed chamber, the vristor and the alloy-type temperature fuse are provide in the closed chamber, with one surface of varistor being close to one surface of the temperature fuse, the leads of them extending outside the closed chamber; the closed chamber is provide with the alloy flux. In the invention, varistor and temperature fuse are integrated, so that the velocity of heat transfer is fase, installation is facility in use.Under the action of the flux, the melted alloy may shrink toward two leads rapidly, becoming two balls, according to different requirement, chosing different melting point and different size of the alloy, matching the varistor of different current, a variety of specification of the varistor can be made by the invention, and can be applied broadly.

Description

Varistor with alloy type thermal fuse

The invention relates to a varistor with an alloy type temperature fuse, which has a fail-safe function, is particularly suitable for a zinc oxide varistor, and is used for overvoltage protection.

Background technique

With its superior nonlinear volt-ampere characteristics, varistors are widely used as overvoltage protection and surge absorbing components for circuits, devices and components. Regardless of whether a varistor is applied to a power line or an electronic circuit, if various types of transient overvoltages occur frequently, the varistor will frequently operate to suppress overvoltage amplitude and absorb and release surge energy, protecting electrical equipment and Components, this will inevitably lead to degradation or even failure of the varistor; when the varistor accepts a temporary overvoltage, the varistor will quickly break down locally and cause a fire. The existing varistor with fail-safe has the following main defects: First, the structure is complicated, such as a conventional die-type thermal trip device or a thermal protection varistor disclosed in Chinese Patent No. CN02222055.0; : As the temperature protection face of the overheat protection structure, the response speed is too slow or the high current impact resistance is weak and easy to fail. For example, the traditional shrapnel type thermal trip device, the organic type thermal fuse, and the alloy type thermal fuse or A safety varistor disclosed in Chinese patent CN00237913.

, the content of the invention '

The present invention aims to provide a varistor having an alloy type temperature fuse which is simple and compact in structure, fast in response speed, and wide in application range, and which can be self-ineffectively protected. '

The invention is completed based on the principle that the varistor and the temperature fuse are integrally formed to form a varistor capable of self-failure protection by using the advantages of the alloy type temperature fuse, and the specific solution is as follows: The invention includes: varistor, alloy The type of temperature fuse, the sealed cavity, the varistor and the alloy type thermal fuse are arranged side by side in the sealed cavity and adjacent to a surface, the pin extends outside the sealed cavity; the sealed cavity is filled with an alloy flux.

The sealed cavity comprises a housing with an opening, and the varistor is arranged in the housing in parallel with the alloy type thermal fuse, and is filled with an alloy flux, and an epoxy sealing material is arranged at the upper opening thereof to form Confined capacity Cavity.

The invention can also be completed as follows: including a varistor, an alloy type temperature fuse, a sealed cavity, the alloy type temperature fuse is disposed in a small casing, and the small casing and the varistor are juxtaposed in the sealed cavity, and An outer wall of the small casing is in close contact with a surface of the varistor, and the pin extends outside the casing; the small casing is provided with an alloy flux.

The sealed cavity includes a housing with an opening, and a front convex portion of the housing extends outwardly to form an accommodating space of the small housing; an epoxy resin sealing material is formed at the opening of the housing to form Closed cavity.

The alloy type temperature fuse is a low melting point alloy wire with pins at both ends. .

The small casing is a casing made of ceramic or other high thermal conductivity and high insulating material, and at least one of the side walls is flat. The alloy type thermal fuse is pre-set in a small housing. The small housing is made of ceramic or other high thermal conductivity and high insulation material, which can save the fluxing material and prevent the dispersion of the flux, and has the function of arc extinguishing. Improve insulation performance.

The invention can be made into a variety of structures according to the above basic structure on the basis of the above basic structure: Two pins: one pin of the alloy type thermal fuse is connected with one pin of the adjacent varistor, and the connection point is sealed In the housing, the other pins of the varistor and the alloy type thermal fuse extend outside the sealed cavity. :

Three pins: The two pins of the varistor extend outside the sealed cavity, one of the pins adjacent to the thermal fuse is connected to one pin of the alloy type thermal fuse; the connection point is sealed in the housing, the alloy type temperature The other pin of the fuse extends beyond the closed cavity.

Four pins: The two pins of the varistor and the alloy type thermal fuse extend outside the sealed cavity, and the pins are not connected to each other.

The varistor is connected in series: two varistor are arranged in the housing; the two pins of the alloy type thermal fuse sandwiched between the two varistors are respectively connected with one of the adjacent two varistor The foot is connected, and the connection point is sealed in the casing; the two varistor are connected in series by a thermal fuse, and the other of the pins extends outside the sealed cavity.

Parallel connection of varistor: Two varistor are provided in the sealed cavity. One of the opposite pins of each other is connected to each other and then connected to one pin of the alloy type thermal fuse. The connection point is sealed in the housing. Piezoresistors are connected in parallel; the temperature fuse is sandwiched between two varistors, two varistors The other two pins and the other pin of the alloy type thermal fuse (which can also be two pins) extend outside the sealed cavity.

Alarm function: The varistor and alloy type temperature fuse in the closed cavity can also be placed next to an alarm device with certain operating temperature characteristics, which can be divided into two parts: normal turn to normally closed or normally closed to normally open. Mode.

The utility model has the function of starting the standby varistor: the varistor and the alloy type temperature fuse in the sealed cavity can also be placed next to the normally open and normally closed switching device with a certain operating temperature characteristic, and the standby varistor After being connected in series with the switching device, the circuit is connected to the circuit. When the switching device is switched from the normally open state to the normally closed state, the standby varistor can be officially connected to the circuit for operation; the standby varistor can also be made to have the same start-up. Next backup varistor function

According to the inventive concept, products of other structures, such as two or more varistors connected in series or in parallel, and the like can be fabricated.

The invention integrates the varistor and the temperature fuse, has the advantages of fast heat transfer speed, convenient and simple installation during use, and has the function of alloy fluxing, so that the molten alloy can be quickly shrunk into balls at two pins, and the invention can be According to different needs, different melting points, different sizes of alloys, and different varistor varistors are used to make varistor of various specifications, which is widely used.

The various structures made by the invention can simultaneously satisfy a plurality of functions: Firstly, various structures made by the invention can meet the requirements of absorbing varistor voltages with different surge currents and different varistor voltages for absorbing lightning voltage and surge voltage. Secondly, when the varistor frequently suppresses the overvoltage amplitude and absorbs and releases the surge energy to cause performance degradation or even failure, the various structures formed by the present invention can have a leakage current of less than 10 millimeters in the varistor. The fail-safe function can be activated at a time (the fail-safe function can also be activated at a lower leakage current, but the on-flow is appropriately reduced). Third, when the varistor is subjected to a temporary over-voltage, the varistor leakage current In the state below about 300 mA, the various structures made by the present invention can initiate a fail-safe function before breakdown of the varistor. If the leakage current is larger or even exceeds 10 amps, the various structures made by the present invention can be The fail-safe function is quickly activated after breakdown of the varistor; fourth, the various structures made by the present invention can improve the absorption and release surge energy

DRAWINGS Figure IB is a schematic view of the fuse of the present invention after being blown;

2A is a schematic view of the basic structure 1 of the present invention;

2B is a schematic view of the basic structure 2 of the present invention;

3A is a schematic structural view of two pin embodiments of the present invention,

3B is a schematic circuit diagram of two pin embodiments of the present invention, and

4A is a schematic structural view of a three-pin embodiment of the present invention,

4B is a schematic circuit diagram of a three-pin embodiment of the present invention

5 is a schematic structural view of a four-pin embodiment of the present invention, FIG. 6A is a schematic structural view of a series connection embodiment of a varistor according to the present invention, and FIG. 6B is a schematic circuit diagram of a series connection embodiment of the varistor according to the present invention;

7A is a schematic structural view of a parallel embodiment of a varistor according to the present invention;

7B is a schematic circuit diagram of a parallel embodiment of a varistor of the present invention,

8A is a schematic structural view of an embodiment of an alarm function provided by the present invention;

8B is a schematic circuit diagram of an embodiment of the present invention with an alarm and an alarm function.

Figure 9: Schematic diagram of the circuit with the embodiment of starting the standby varistor of the present invention

Where: 1 housing; 2 'varistor; 3 varistor pin; 4 alloy type thermal fuse; 5 fuse bow I foot; 6 epoxy resin sealing material; 7 fuse, 8 small shell, 9 often Open-closed normally closed or normally closed to normally open type alarm device with certain operating temperature characteristics, 10 normally open to normally closed switching device'

detailed description

Example 1 : . . '

As shown in FIG. 2A, an embodiment of the basic structure 1 of the present invention includes: a housing 1, a varistor 2, and an alloy type thermal fuse 4; the varistor 2 and the alloy type thermal fuse 4 are immediately adjacent to each other and are mounted on the shell. In the body 1, the casing 1 is provided with an alloy fluxing agent 7, and the upper portion thereof is sealed with an epoxy resin sealing material 6 to form a sealed cavity, and the varistor pin 3 and the fuse pin 5 are provided. Outside the opening of the housing 1.

In use, when the varistor 2 generates heat due to various factors, heat can be transmitted to the surrounding alloy flux 7 through its surface layer, and then the alloy flux 7 transfers heat to the alloy fuse 4 until the alloy After being heated, it melts and rapidly contracts to the two fuse pins 5 by the action of the alloy flux 7 (Fig. 1A, Fig. 2B), thereby cutting off the circuit and detaching the varistor 2 which is about to deteriorate from the circuit.

Example 2:

2B, is an embodiment of the basic structure 2 of the present invention, including a varistor 2, an alloy type thermal fuse 4, a housing 1 and a small housing 8.; an alloy type thermal fuse 4 and a fuse breaker 7 The inside of the small casing 8 made of ceramic or other high thermal conductivity and high insulating material is sealed, and the small casing 8 is sealed with an epoxy sealing material 6. The inner side of the small casing 8 is in close contact with the varistor 2 A surface is then placed into the housing 1 together, and the opening of the housing 1 is sealed with an epoxy sealant 6 to form a sealed cavity.

When heat is generated by various factors of the varistor 2, heat can be directly transmitted to the small casing 8 through the surface layer thereof, and the small casing 8 immediately transfers heat to the alloy fuse 4 until the alloy is heated and then melted and alloyed in the flux. Under the action of 7, the two fuse pins 5 are quickly shrunk, thereby cutting off the circuit and detaching the varistor 2 which is about to deteriorate from the circuit.

Example 3:

The two pin embodiments of the present invention, as shown in FIGS. 3A and 3B, the present embodiment includes a varistor 2, an alloy type thermal fuse 4, a housing 1 and a small housing 8; the front wall of the housing 1 extends outward An outer convex portion 11 forms an accommodating space of the small casing; the alloy type thermal fuse 4 and the fluxing aid 7 are first loaded into a small casing 8 made of ceramic or other high thermal conductivity and high insulating material, and the small casing The 8-port portion is sealed with an epoxy resin sealing material 6, and the inner side of the small casing 8 is closely attached to a surface of the varistor 2, and then the two are placed together in the casing 1 (refer to FIG. 2B); The first pin 3a of the varistor 2 is connected to the second pin 5a of the alloy type thermal fuse 4 and sealed in the casing; the second pin 3b of the varistor 2 and the first pin 5b of the alloy type thermal fuse 4 Extending outside the casing; sealing the opening of the casing 1 with an epoxy sealing material 6 to form a sealed cavity.

Example 4: '

For the three pin embodiments of the present invention: as shown in FIGS. 4A and 4B, the difference from the embodiment '3 is: The two pins 3a, 3b of the varistor 2 extend outside the housing, one of the pins. 3a is connected to one pin 5a of the alloy type thermal fuse, and the connection point is sealed in the casing; the other pin 5b of the alloy type thermal fuse 4 extends outside the casing i. The epoxy resin seals the opening of the casing 1 ' seal.

Example 5

For the four-pin embodiment of the present invention, as shown in FIGS. 5A and 5B, the difference from Embodiment 3 is: The two pins 3a, 3b of the varistor 2 and the two pins 5a, 5b of the alloy type thermal fuse 4 extend outside the housing, and the pins are not connected to each other; the housing 1 is sealed with an epoxy resin sealing material 6. The opening is sealed.

Example 6:

The embodiment of the double varistor of the present invention is as shown in FIGS. 6A and 6B: comprising two varistor 2, 2', an alloy type thermal fuse 4, a housing 1 and a small housing 8; The alloy type thermal fuse 4 and the flux breaker 7 are installed in the small casing 8, and the small casing 8 is sealed with the epoxy sealing material 6; the small casing 8 is sandwiched between the two varistor 2, 2 Between the one outer wall of one side of the first varistor 2 is in close contact with the outer surface of the second varistor 2 ′, and is mounted on the surface of the second varistor 2 ′; A pin 5a of the fuse 4 is connected to a pin 3a of the first varistor 2, and the other pin 5b of the alloy type thermal fuse 4 is connected to a pin 3a' of a second varistor 2', and Sealed in the housing 1; the first and second varistors 2, 2' are formed in series, and the other nips 3b, 3b' of the first varistor and the second varistor extend outside the housing. The epoxy sealant 6 seals the opening of the housing 1. This embodiment can achieve the superposition of two varistor voltages. When a higher varistor voltage requirement is difficult to achieve in a single varistor, it can be divided into two lower varistor voltage varistors! 3⁄4 is blocked and shared, and it has fail-safe function.

Example 7

The parallel varistor embodiment of the present invention, as shown in FIGS. 7A and 7B, includes two varistor 2, 2', an alloy type fuse 4, a housing 1 and a 'small housing 8, and Embodiment 6 The difference is that: one of the two varistor 2, 2' pins 3a and 3a' are connected to each other, and then a pin of the alloy type thermal fuse 4 sandwiched between the two varistors Connection 5a, two varistors are formed in parallel; the other two pins 3b, 3b'' of the varistor and the other of the alloy type thermal fuses. The pins 5b extend outside the housing; respectively; The mouth of the housing 1 is sealed. In this embodiment, the varistor voltage can be kept constant, the flow rate is increased, and the fail-safe function is provided. '

The principles of Embodiments 5 and 6, can also be made in series or in parallel of two or more varistors.

Example 8··

The invention has an alarm function embodiment. On the basis of the structures of the embodiments 2 to 7, an alarm device 9 having a certain operating temperature characteristic can be placed beside the alloy type thermal fuse 4, and is divided into a normally open or normally closed or From normally closed to normally open two modes; the alarm device 9 can turn on or off the indicator light connected to it, and thus function as an alarm. . ' As shown in FIG. 8, the single varistor has a single varistor with an alarm function, and the embodiment includes a varistor 2, an alloy type thermal fuse 4, a housing 1 and small housings 8 and 8'; The front wall and the rear wall of 1 each extend outwardly with an outer convex portion 11, 12 to form an accommodation space for the small casings 8 and 8';'the alloy type thermal fuse 4 and the flux breaker 7 are first loaded into the ceramic Or in the small casing 8 made of other high thermal conductivity and high insulating material, the mouth of the small casing 8 is sealed with the epoxy sealing material 6; at the same time, the alarm device 9 for temperature characteristics is loaded into the other small casing 8' The inner side of the small housing 8 abuts against a surface of the varistor 2, and the inner side of the other small housing 8' abuts against the other surface of the varistor 2, and then the three are placed together in the housing 1. The mouthpiece of the casing 1 is sealed with an epoxy sealant 6.

Example 9

The invention is provided with an embodiment of starting the standby varistor. As shown in FIG. 9, on the basis of the structures of the embodiments 2 to 7, the alloy type temperature fuse 4 can be placed with a certain operating temperature characteristic and is often changed from the normal to the normal. Closed device 10, device 10 can be connected in series with another spare varistor (such as the structure of Embodiments 1 to 8) and then connected in parallel in the line, so that when the temperature of varistor 2 (in-line) reaches a specified temperature , starting the second varistor into the working state; and implementing the multi-stage standby varistor. Embodiment 8 can also be carried out simultaneously with Embodiment 7.

In Embodiments 3 to 8, when the varistor 2 generates heat due to various halogens, heat can be transmitted through the surface layer to the small casing 8 made of ceramic or other high thermal conductivity and high insulating material and can be permeable thereto. The foot is transferred to the alloy fuse 4, the alloy flux 7, until the alloy is heated and melted and rapidly shrinks to the two fuse pins 5 under the action of the alloy flux 7 (as shown in Fig. 1A, IB), thereby cutting off the circuit and will soon deteriorate The varistor 2 is detached from the line, and the thermal reaction speed is fast. The structure is simple and compact.

For the application of the first to seventh embodiments, the varistor 2 can be used for splicing the lead wires 3a, 3b on both sides of the sintered varistor bare chip, and the finished product form sealed by using the epoxy resin powder. The cavity and the alloy type thermal fuse 4 are combined; it can also be used on the silver layer on the dies of the varistor after sintering. A round copper piece is soldered, and the lead 3b is soldered on the round copper piece, and the other A silver layer can be connected as a pin 3a to the thermal fuse 5a and placed in the housing. The sealing portion in the housing and the remaining gap portion are filled with epoxy resin.

Industrial applicability

The invention is provided with a varistor of an alloy type temperature fuse, has a simple and compact structure, is convenient to use, and can be industrially produced in large quantities, and has good industrial applicability.

Claims

Rights request

1. A varistor having an alloy type temperature fuse, comprising: a varistor, an alloy type temperature fuse, a sealed cavity, a varistor and an alloy type temperature fuse arranged side by side in a sealed cavity and a surface Immediately adjacent to the pin, the pin extends outside the sealed cavity; the sealed cavity contains an alloy flux.

2. The varistor provided with an alloy type thermal fuse according to claim 1, wherein: said sealed cavity comprises a housing with a mortise, and the varistor and the alloy type thermal fuse are juxtaposed. The casing is filled with an alloy flux, and an epoxy sealing material is disposed at an upper opening thereof to form a sealed cavity.

3. The varistor provided with an alloy type thermal fuse according to claim 1 or 2, wherein the alloy type thermal fuse is a low melting point alloy wire having pins at both ends.

4. A varistor provided with an alloy type temperature fuse, comprising: a varistor, an alloy type temperature fuse, a sealed cavity, an alloy type temperature fuse disposed in a small casing, a small casing and a pressure The varistor is juxtaposed in the sealed cavity, and an outer wall of the small casing is in close contact with the surface of the varistor, and the pin extends 'outside the casing; the small casing is provided with an alloy flux.

5. The varistor provided with an alloy type thermal fuse according to claim 4, wherein: said sealed cavity comprises a housing having an opening, and a front wall of the housing extends outwardly from an outer convex portion. The housing of the small-sized housing is provided with an epoxy sealing material at the opening of the housing to form a sealed cavity.

6. The varistor provided with an alloy type thermal fuse according to claim 4 or 5, wherein: the alloy type thermal fuse is a low melting point alloy wire having pins at both ends thereof.

7. The varistor having an alloy type thermal fuse according to claim 4, wherein: said small housing is a ceramic or other housing made of high thermal conductivity and high insulating material, at least one side. The wall is flat. ·

8. The varistor provided with an alloy type thermal fuse according to claim 4, wherein: a lead of the alloy type thermal fuse is connected to a pin of the varistor and sealed in the casing; The other pin of the resistor and the other pin of the alloy type thermal fuse extend outside the housing, respectively.

9. The varistor provided with an alloy type thermal fuse according to claim 4, wherein: the two pins of the varistor extend outside the housing, wherein a pin of the varistor adjacent to the thermal fuse is provided. Connected to one pin of the alloy type thermal fuse, the connection point is sealed in the housing; the alloy type thermal fuse is another A pin extends outside the housing.

10. The varistor provided with an alloy type thermal fuse according to claim 4, wherein the varistor and the alloy type thermal fuse have pins extending outside the casing, and the pins are not connected to each other.

11. The varistor provided with an alloy type temperature fuse according to claim 4, further comprising: a second varistor, which is provided with an alloy type temperature fuse and is sandwiched between two varistor The outer wall of one side is in close contact with one surface of the first varistor, and the outer wall of the other side is closely attached to a surface of the second varistor and is mounted in the sealed cavity; wherein a pin of the alloy type thermal fuse is Connected to a pin of the first varistor, one pin of the alloy type thermal fuse is connected to the other pin of the second varistor, and is sealed in the casing; the first and second varistor are connected in series, The other one of the first varistor and the second varistor extends outside the housing.

12. The varistor provided with an alloy type thermal fuse according to claim 4, further comprising: a second varistor, an alloy type temperature fuse having a small case sandwiched between the two varistor Wherein one of the outer walls is in close contact with a surface of the first varistor, and the other outer wall is closely attached to a surface of the second varistor and is housed in the sealed cavity; wherein the first varistor is cited The pin is connected to one pin of the second varistor, and is connected to one pin of the alloy type thermal fuse, and the two varistors are connected in parallel; the other pin and the alloy of the second varistor of the first varistor The other pin of the type thermal fuse extends outside the housing. +

13. The varistor provided with an alloy type temperature fuse according to claim 4, wherein: an alarm device having a certain operating temperature characteristic is disposed beside the alloy type temperature fuse in the housing, and is divided into a normally open switch. Normally closed or normally closed to normally open.

14. The varistor provided with an alloy type thermal fuse according to claim 4 or 13, comprising: a varistor, an alloy type thermal fuse, a housing and two small shells; a front wall of the housing and The rear wall extends outwardly with an outer convex portion to form a accommodating space of two small casings; the alloy type thermal fuse and the fluxing aid are installed in a small casing, and the mouth portion is sealed with an epoxy sealing material; temperature characteristics The alarm device is mounted on another small casing; the inner sides of the two small casings are respectively abutted against the two surfaces of the varistor, and the three are disposed in the casing, and the opening of the casing is sealed with an epoxy sealing material. . ,